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Incoming links: Invariant manifold
Invariant torus Created 2026-09-29 Updated 2026-10-14
An invariant torus is a subset homeomorphic to a torus and preserved by a flow. In action-angle variables, an integrable Hamiltonian flow moves linearly in the angular coordinates of each regular invariant torus.
The torus is a particular invariant manifold; its toroidal topology is an extra condition beyond invariance.